Tie-down devices are used to secure rotorcraft, such as helicopters, to a surface suitable for supporting the rotorcraft (hereinafter “support surface”). Support surfaces include, for example, landing surfaces such as a landing pad or the deck of a ship. Tie-down devices may be placed at locations on the rotorcraft referred to as tie-down points. Tie-down devices may also be found on the support surface. Fasteners, such as ropes, straps, chains, and the like may be used to couple a rotorcraft tie-down device to a support surface tie-down device by means of hooks or clips on each end. Hereinafter, “tie-down assembly” refers to the combination of components such as tie-down devices, fasteners, and hooks or clips suitably configured to couple a rotorcraft tie-down point to a support surface. As such, when a rotorcraft tie-down device has a fastener coupled to it, the rotorcraft tie-down device is referred to as “attached”. Likewise, when a given tie-down assembly is coupled on one end to a rotorcraft and on another end to a support surface, the tie-down assembly is referred to as “attached.”
Attached tie-down assemblies protect the rotorcraft from possible damage during, for example, rough seas and/or windy conditions. Before taking off, all tie-down assemblies and tie-down devices must be detached; however, sometimes, during exigent circumstances or emergency situations, one or more rotorcraft tie-down devices may be inadvertently left attached, limiting rotorcraft mobility and perhaps causing the rotorcraft to flip over. An attempted take-off occurs when the rotorcraft begins to lift off of the support surface. A noticeable amount of helicopter accidents are related to attempted take-offs while rotorcraft tie-down devices are attached, and the reported number of accidents does not reflect attempted take-off events with attached rotorcraft tie-down devices that did not result in reportable accidents.
Accordingly, it is desirable to provide a rotorcraft tie-down detector system that detects attached tie-down devices and generates a warning before and during an attempted take-off if at least one rotorcraft tie-down device remains attached. Such a tie-down device detector system would increase situational awareness and safety.
Other desirable features will become apparent from the following detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.